In general, a touch panel is used as an input device for a personal computer, a portable communication device, and other personal information processing devices to allow a user to input information by directly touching the touch panel using a hand or a pen.
Recently, the touch panel is employed in various information processing devices because the touch panel has advantages of a simple structure with less malfunction and easy portability, and a user can easily input characters without other input devices and easily know the usage of the touch panel.
The touch panel may adopt a capacitive type, in which an equipotential is formed on a conductive layer and a position of upper and lower plates where voltage variation occurs is sensed according to the touch of the user.
According to the general usage of the touch panel, the user touches an icon of a switch having a predetermined function using a finger from among selection switches displayed on the touch panel, thereby selectively driving a desired function. At this time, if a pitch of the switches (interval between adjacent switches) is narrower than a finger width, it is difficult to select the desired switch. In general, the finger width of an adult is about 8 mm, so it is undesired if the pitch is smaller than 8 mm. In addition, it is also meaningless if the resolution for a touch position of the finger is set to 8 mm or above. For this reason, a line pitch of the touch panel is set to about 8 mm.
However, different from the selection of the switches, when the user sketches or writes characters using the touch panel, the input work may be facilitated as the resolution for the touch position becomes high. In particular, when the input work is performed by using an article having a sharp tip, such as a stylus pen which is used instead of the finger, the high resolution is desired.